The technique of medullary stimulation, also known as stimulation of the spinal cord or neurostimulation, is used to provide relief to patients suffering from severe neuropathic pain. This technique consists in emitting electric pulses in the direction of the nerve fibres of the spinal cord of a patient, through the intermediary of at least one multi-contact electrode. The at least one electrode may be old generation (mono-column) or new generation (multi-column).
Medullary stimulation may be applied by surgical or percutaneous route (in this case, the central nervous system is stimulated; the stimulation is triggered from the electrode in the vertebral canal) or instead it may be sub-cutaneous nervous stimulation (the peripheral nervous system is then stimulated). To do so, the electrode has been surgically implanted beforehand on the spinal cord, or in sub-cutaneous tissues, at the level of the painful zone. “At the level of the painful zone” is taken to mean:                for sub-cutaneous stimulation, in a region of the painful zone        for medullary, percutaneous or surgical stimulation, with regard to a certain region of the spinal cord in the vertebral canal, at the level of which are centralised the projections pertaining to a painful peripheral cutaneous zone (for example, a painful region of the lower limb is projected onto the level of the medullary region, situated at the level of the thoracic vertebrae T9 to T11).        
The electrode is connected to a control box making it possible to activate the pads of the electrode in order to generate a controlled electric field. The electric field stimulates a neuronal population, which causes a paraesthesia leading to a relief of the pain.
The choice of the electrode(s) is crucial. In fact the results are variable as a function of the therapeutic tool used (more or less sophisticated electrodes; percutaneous or surgical electrodes, conventional or new generation electrodes, mono-column or multi-column electrodes, surface electrodes of more or less limited cover, etc.). The choice of the therapeutic tool is made as a function of pain quantification parameters, such as the size or instead the location of the painful zone. In fact, the evaluation of these parameters is a key step, making it possible to choose appropriately the electrode(s) to implant.